Experiments were converned with the initial ocular following responses to transient ramp movements of the visual scene in monkeys. These tracking mechanisms are important for the stabilization of gaze which is so necessary for good visual acuity. Responses had unexpectedly short latencies (50-55 msec) and were almost machine-like in their consistency. Restricting the regions of retina stimulated by the drifting scene revealed that the earliest responses emanate from peripheral retinal inputs. It was also discovered that the magnitude of these transient tracking responses was every sensitive to the occurrence of saccadic eye movements: responses were always greatest to ramps delivered immediately after saccadic eye movements and diminished progressively as the post-saccadic interval increased, being reduced by about 1/2 after 300 msec. Additional experiments were undertaken concerning the gain of the tracking system mediating these responses: if the gain were too high, the eyes would tend to overshoot the moving scene, whereas a low gain would result in undershoot. To ascertain whether the gain is normally subject to adaptive regulation to minimize these problems, animals were exposed to repeated velocity-step movements of the scene that first initiated ocular following and then transiently induced retinal events resembling those expected during undershoot or overshoot. Over a 3-day period, clear adaptive changes were seen in the tracking responses to transient movements: repeated exposure to steps inducing overshoot resulted in a severe attenuation of 50% or more, and steps inducing undershoot resulted in even greater increases. The adaptation was also directionally selective: responses in any one of the primary directions up, down, left, or right, could be altered independently. Further, if the velocity step adaptation paradigm involved 90 degree changes in the direction of movement (speed constant), tracking responses acquired corresponding orthogonal components. These experiments show that ocular following responses are rapidly initiated, highly stereotyped, and subject to extensive, visually-mediated adaptive regulation.